Image forming apparatus and sheet feeding cassette

Abstract

An image forming apparatus includes: a main body for performing an image forming operation, and a sheet feeding cassette detachably mounted in the main body. The sheet feeding cassette includes: a pair of cursors spaced apart a predetermined distance and facing each other for regulating a size of a recording sheet stored in the sheet feeding cassette; a rack provided on each of the pair of cursors; a pinion provided between the racks and engaged with each of the racks; and a boss for supporting the pinion rotatably, the pair of cursors being movable in conjunction with each other by the way of racks and the pinion. Further, a rib is provided adjacently to the pinion at a predetermined space. The rib is operable to come in contact with the pinion to thereby keep the pinion from moving in a radial direction.

1. An image forming apparatus comprising:
 a main body for performing an image forming operation; 
 a sheet feeding cassette detachably mounted in the main body, the sheet feeding cassette including:
 a pair of cursors spaced apart a predetermined distance and facing each other for regulating a position of a recording sheet stored in the sheet feeding cassette; 
 a rack provided on each of the pair of cursors; 
 a pinion provided between the racks and having an outer peripheral surface and being formed with teeth arranged in a circle for engagement with each of the racks, the pinion including an annular flange that is coaxial with the circularly arranged teeth and has a diameter larger than the circularly arranged teeth; and 
 a boss for supporting the pinion rotatably, the pair of cursors being movable in conjunction with each other by the way of the racks and the pinion; and 
 
 a rib provided adjacently to the annular flange of the pinion at a predetermined space from an outer peripheral surface of the annular flange in an insertion direction of the sheet feeding cassette, the rib including a circular receiving portion disposed to contact the outer peripheral surface of the annular flange in the insertion direction of the sheet feeding cassette to keen the pinion from moving in a radial direction, a pinion receiving surface of the circular receiving portion having a curvature radius that is substantially the same as a curvature radius of the outer peripheral surface of the annular flange. 
 
   
   
     2. An image forming apparatus according to  claim 1 , wherein:
 the pair of cursors face each other at a predetermined space in an insertion and withdrawal direction of the sheet feeding cassette relative to the main body and are adapted for regulating in the insertion and withdrawal direction the position of the recording sheets to be stored in the sheet feeding cassette; 
 one of the racks extends in the insertion and withdrawal direction from the cursor on which the one rack is provided to the opposite cursor; and 
 the rib is provided so as to come in contact with a rear part of the pinion in the insertion direction of the sheet feeding cassette to keep the pinion from moving in the insertion direction. 
 
   
   
     3. An image forming apparatus according to  claim 1 , further comprising:
 a rail member provided in the sheet feeding cassette for movably supporting the pair of cursors, the boss being integrally formed on the rail member, wherein 
 the rib is integrally formed on the rail member. 
 
   
   
     4. A sheet feeding cassette detachably mounted in a main body, comprising:
 a pair of cursors spaced apart a predetermined distance and facing each other for regulating a position of a recording sheet stored in the sheet feeding cassette; 
 a rack provided on each of the pair of cursors; 
 a pinion provided between the racks and having an outer peripheral surface and formed with teeth arranged in a circle for engagement with each of the racks, the pinion including an annular flange that is coaxial with the circularly arranged teeth and has a diameter larger than the circularly arranged teeth; 
 a boss for supporting the pinion rotatably; and 
 a rib provided adjacently to the annular flange of the pinion at a predetermined space, from an outer peripheral surface of the annular flange in an insertion direction of the sheet feeding cassette, the rib including a circular receiving portion disposed to contact the outer peripheral surface of the annular flange in the insertion direction of the sheet feeding cassette to keep the pinion from moving in a radial direction; a pinion receiving surface of the circular receiving portion having a curvature radius that is substantially the same as a curvature radius of the outer peripheral surface of the annular flange, wherein: 
 the pair of cursors are movable in conjunction with each other by the way of the racks and the pinion. 
 
   
   
     5. A sheet feeding cassette according to  claim 4 , wherein:
 the pair of cursors face each other at a predetermined space in an insertion and withdrawal direction and are adapted for regulating in the insertion and withdrawal direction the position of the recording sheets to be stored in the sheet feeding cassette; 
 one of the racks extends in the insertion and withdrawal direction from the cursor on which the one rack is provided to the opposite cursor; and 
 the rib is provided so as to come in contact with a rear part of the pinion in the insertion direction of the sheet feeding cassette to keep the pinion from moving in the insertion direction. 
 
   
   
     6. A sheet feeding cassette according to  claim 4 , further comprising:
 the rail member provided in the sheet feeding cassette for movably supporting the pair of cursors, the boss being integrally formed on the rail member, wherein 
 the rib is integrally formed on the rail member. 
 
   
   
     7. An image forming apparatus according to  claim 1 , wherein the pinion includes a central aperture and wherein the boss extends through the central aperture of the pinion for supporting the pinion rotatably. 
   
   
     8. An image forming apparatus according to  claim 1 , wherein the outer peripheral surface of the pinion is disposed radially outwardly from the boss and radially inwardly from the rib. 
   
   
     9. An image forming apparatus according to  claim 8 , wherein the outer peripheral surface of the pinion that is contacted by the rib defines a radially outermost part of the pinion. 
   
   
     10. An image forming apparatus according to  claim 4 , wherein the pinion includes a central aperture and wherein the boss extends through the central aperture of the pinion for supporting the pinion rotatably. 
   
   
     11. An image forming apparatus according to  claim 4 , wherein the outer peripheral surface of the pinion is disposed radially outwardly from the boss and radially inwardly from the rib. 
   
   
     12. An image forming apparatus according to  claim 11 , wherein the outer peripheral surface of the pinion that is contacted by the rib defines a radially outermost part of the pinion.